smokey exhaust...sometimes

[Phantom17]

Sometimes I get some smoke from my exhaust (water exhausting through prop center is slightly blackened, and sometimes it barely smokes at all. It does it both when warmed up, and at cold start? <br /><br />OMC GM inline 4,

 

[trog100]

Re: smokey exhaust...sometimes

black smoke is sign of a rich mixture.. not unusual when the engine is cold and the choke is in operation.. but it shouldnt do it when warmed up..<br /><br />check that your choke is comming off.. it might not be..<br /><br />trog100

 

[Phantom17]

Re: smokey exhaust...sometimes

The water is slightly blackened, the smoke is grey, an oil smell too.

 

[trog100]

Re: smokey exhaust...sometimes

whiteish smoke is just steam.. blue-ish perhaps blueish grey is oil burning.. black is rich mixture..<br /><br />now u are as wise as i am.. he he<br /><br />are your water temps okay.. is water circulating as it should.. your impellor isnt melting or something wierd like that..<br /><br />the first thing to do thow is check the choke.. make sure its coming off.. no point in going further till u check that..<br /><br />how long its been doing it might be of relevance too.. i assume its just when its idling..??<br /><br />trog100

 

[Phantom17]

Re: smokey exhaust...sometimes

I bought it in January, started after the fogging burned off, could be choke as I have a hard time idling in the water, but not on land with hose. Really has to warm up to clear up. I was thinking possible carb rebuild. Sprayed some carb cleaner in it while running yesterday and it seemed to run cleaner the next day, I also raised the idle another 100 rpm's to help the stall problem in the water. Used it already about 10 hours and 1 tank of gas already this season, of 10 hours, 9.75 was under 3000 rpms, no place to open it up more than that........yet......

 

[trog100]

Re: smokey exhaust...sometimes

in the water the exhaust has to exit under water and this causes more back pressure than on the hose.. running slightly slower is normal.. the bottom line is does it keep going reliably when u put it in gear cos it slows down even more then.. the idle speed (throttle stop screw) does need adjusting with the boat in the water.. doing it any other way is just guessing..<br /><br />having cleared that one up.. i cant be of much more help other than to say it dont sound super bad or expensive to fix.. a carb kit and bit of tweaking might well fix it..<br /><br />trog100

 

[rodbolt]

Re: smokey exhaust...sometimes

hello<br /> if it has an electric choke heater coil check for voltage at the choke coil heater wire to ground and do a resistance test between the terminal on the choke and ground. the coils have a tendancy to fail.

 

[Nos4r2]

Re: smokey exhaust...sometimes

Has the engine been stood a long time?<br /><br />If it has it could well be the valve stem seals completely shot. I've had the same problem on bikes where the seals have cracked and are allowing oil down the valve guide.

 

[Phantom17]

Re: smokey exhaust...sometimes

I went to poke around trying to lean out the carb a bit and found that the choke piston was in fact a washer, between 2 nuts tightened on a bolt, and popped into the choke housing, held in by orange gasket cement........parts are on the way.....It amazes me the things people do....total for parts $9.00, plus $4.00 in gas (as apposed to $10 to ship). Cost of finding this now instead of on the water...priceless.

 

[magregor22]

Re: smokey exhaust...sometimes

Nos4r2, dried up valve stems usually burn blue not black...don't they? just a thought. Oil burns blue,rich fuel burns black. H/J

 

[Nos4r2]

Re: smokey exhaust...sometimes

yeah they do- I was wondering about the oil smell though. Hard to tell when you aint there I guess.